The invention relates to an interceptor for the continuous removal of solid matter from a mixture of solids and liquid, the interceptor including a screening drum rotating in a given direction while operating, a jacket of the drum having screening openings, such as sieve openings. An inlet feeds the mixture to the outer surface of the drum jacket, whereby the liquid enters the drum through the openings in the jacket, and the solid matter remains on the outer surface of the drum jacket. The solid matter is removed from the outer surface of the drum jacket through a solids discharge, and a liquid outlet discharges the cleansed liquid.
Various types of interceptors in the form of screening drums are used. Generally, the mixture of solids and liquid is fed to the interior of the screening drum, the screened particles remaining inside the drum and the cleansed liquid emerging to the outside of the drum. For many purposes, this type of screening drum operates satisfactorily, but the discharge especially of all of the granular particles from the interior of the drum presents problems.
German Pat. No. 25 01 547 teaches an interceptor of the screening drum-type wherein the mixture is fed to the exterior of a drum. For this purpose, a box-type feeding mechanism is fitted to the drum jacket above the central plane of the drum. The liquid drops from there in a free fall through the interior of the drum and re-emerges through the openings in the jacket to the outside of the drum in the bottommost part of the drum jacket. The screened particles are carried away on the surface of the drum jacket and over the top of the drum and are removed by means of a plate reaching almost as far as the drum jacket.
Even though this known device simplifies the discharge of the removed solids, the throughput performance leaves much to be desired. Moreover, due to the great depth of fall of the liquid, the hydraulic losses are rather substantial.